Adobe Premiere (expensive) or Premiere Elements (not quite as expensive) will do a decent job however if you're cheap like me you can do it in Windows Movie maker.
Just import all the individual images, click "Edit" then change the interval to something like 0.04 seconds (for 25 frames/sec) and you're done.
Here's a very rough example ...
http://www.youtube.com/watch?v=2EZm2E_Su_o